Introduction: Tuberculosis is one of the major causes of mortality and morbidity in childhood. It is challenging to diagnose in childhood population due to difficulty in collection of sample and paucibacillary nature. Despite of considering mycobacterium culture as gold-standard test, it is time consuming (4-8 weeks) while traditional ZN stain is poorly sensitive or specific. In 2013, WHO endorsed Cartridge Based Nucleic Acid Amplification Test (CBNAAT) for diagnosis of TB. Still, there is lack of adequate research on TB detection efficacy of CBNAAT over ZN stain or culture. Aims & Objective: Comparison of CBNAAT over ZN stain & mycobacterium culture, in terms of Sensitivity, Specificity, Positive Predictive Value, Negative predictive value. Materials & Methods: Total of 565 patients admitted to Paediatric Medicine department over 2 years from July 2017 to July 2019 with clinical signs (radiological) and symptoms of local & disseminated tuberculosis and history of close contact were selected and grouped under pulmonary and extra-pulmonary categories. Each sample was analyzed by CBNAAT, ZN smear and culture.